Microsoft Lifts XP Mode Hardware Requirement 205
An anonymous reader writes "This week, Microsoft published a patch that allows Windows XP Mode to run on PCs without hardware-assisted virtualization. Which begs the question: Why the bizarro requirement in the first place? Was it an honest attempt to deliver an 'optimal' user experience? Or simply a concession to the company's jilted lover, Intel Corporation — 'a kind of apology for royally screwing up with the whole Windows Vista “too fat to fit” debacle,' as the blog post puts it."
Re:My best guess.... (Score:5, Informative)
Taking perfectly good hardware and disabling functionality and then selling it a discount isn't new. It certainly isn't new for Intel. Remember the SX series of 386s and 486s, with the FPU disabled, though still on the chip?
Re:My best guess.... (Score:2, Informative)
Yes, I have known Intel for a long time *sigh*.
Just a minor correction... The SX series for the i386 was that the data bus was at half width (16-bit)... The SX for the i486 was indeed a disabled FPU. (Remember the Overdrives? Simply a i486 CPU that disabled the original i486SX)... Aaaah, going down the memory lane.
AMD was supported too (Score:2, Informative)
ars technica [arstechnica.com]
Thanks for pointing that out ColdWetDog.
Re:My best guess.... (Score:5, Informative)
What about those 386 PCs that had a turbo button that would allow it to run at twice the speed (66 MHz instead of 33 MHz)? Nobody ever turned it off, so why have the button in the first place?
For older games built for 33MHz processors that utilized the clock rate for timing.
It's supposed to be disabled by default (Score:3, Informative)
It's to prevent hypervisor based rootkit attacks
https://www.microsoft.com/taiwan/whdc/system/platform/virtual/CPUVirtExt.mspx [microsoft.com]
For systems that are destined for a server role (and for only these systems), enable the virtualization extensions. The threat of running malicious code as an administrator on servers is reduced through Windows Server policies and organizational best practices.
For systems that are destined for a client role, disable (and lock off) the virtualization extensions.
For systems that might be deployed in either a server or client role (such as high-end workstations), it would be prudent to disable the extensions by default.
Re:My best guess.... (Score:5, Informative)
It's quite likely that this is done due to manufacturing defects that prevent some chips from running at the maximum speed. Testing is done to find the highest stable speed, and it's altered fix that speed as the max.
Virtual PC blog (Score:5, Informative)
Explanation of this decision [msdn.com] from Virtual PC blog:
Why is Microsoft making this change to Virtual PC now?
Because of you :-) We have heard loud and clear from customers that they need to be able to run Windows Virtual PC and Windows XP Mode on systems that do not have hardware virtualization support. So we are going to enable this.
Why did Microsoft release Windows Virtual PC without this in the first place?
There are two main reasons here.
The first is that we believe that customers will get the best virtualization experience on computers with hardware virtualization support. This has not changed – and even though we are releasing this update I would strongly encourage anyone who is looking at buying a new computer, and intends to use virtualization, to make sure that they get a system that is capable of supporting hardware virtualization.
The second is that we had hoped that by the time Windows Virtual PC released – hardware virtualization support would be prevalent enough that this would not be an issue. We were wrong on that. Bummer.
Re:My best guess.... (Score:3, Informative)
All chips in the same family come off the same die. Defects and such make each capable of running different maximum speeds. Yes, some are just gimped for the hell of it but they're all from the same die anyway. Which makes perfect sense, it's not always a scam, some chips just aren't capable of running at the higher speeds. It is pretty much always done this way, it's how CPU manufacturing works (one die, different speeds).
Re:seems a bit of a conspiracy theory to me (Score:2, Informative)
Also, it's not like hardware virtualization is exceedingly rare, either. On current AMD processors, for example, only the Sempron line doesn't support it. You also don't need to turn it on in the BIOS on AMD processors either: It either has it or it doesn't. It was actually a safe bet. I'm deliberately pointing out AMD's processors here, too, to show that it really couldn't have been a concession to Intel.
Re:My best guess.... (Score:2, Informative)
Wing Comander needed it on my friends computer (and maybe mine I forget).
When it started it asked you if your computer was fast or slow. allowing for 4 combinations of turbo and game speed.
one worked on my computer, another on my friends, and 3 other combinations failed to work for either of us.
Ars has a much better write up (Score:5, Informative)
http://arstechnica.com/microsoft/news/2010/03/microsoft-removes-vm-hardware-requirements-from-xp-mode.ars [arstechnica.com]
Why the hell is this Exo-Blog post being cited? The author of TFA doesn't cite a goddamn thing.
Re:My best guess.... (Score:2, Informative)
Just recently I got to look after a defective laptop (RAM module was broken...) and I looked in the BIOS. The CPU could do hardware virtualization, but by default it was disabled in the BIOS. Why? I have no idea...
Even worse, I have a Gateway "netbook" (it's a 12") with an Athlon 64 processor, marketed and sold as such, and with AMD-V in the hardware, but it's disabled in the BIOS and there is no option to enable it. I knew Gateway was lame, but damn. Never again.
Re:My best guess.... (Score:3, Informative)
The screening process lowers the cost of all their processors because it allows Intel to salvage a saleable product that would otherwise have to be tossed out at %100 loss if marginal processors couldn't be restricted to operating conditions where their reliability is guaranteed. There is no nefarious plotting involved here. It's a natural response to the difficulty of making high-performance devices with small feature sizes.
Aren't You the Pedant (Score:4, Informative)
In common English, as practiced by most people "begs the question" no longer means "petitio principii". It now means "this information begs that a question be asked, that wasn't".
Of course, we are in a transition. "Begs the question" in taken as logical fallacy by some, and as colloquial expression by others.
There is a perfectly reasonable expression used to replace "Begs the question" -- circular reasoning.